The present invention relates to a disposable electrode which is to be used in a defibrillator, and in which the expiration date of the disposable electrode can be recognized, and also to an automatic information recognition apparatus for the disposable electrode.
In a defibrillator such as an automatic external defibrillator (AED), a disposable electrode is used to facilitate miniaturization and portability. A disposable electrode uses a gel material at a portion of the electrode which is to be contacted with a patient's body. When the gel is dried, the disposable electrode cannot be used. Therefore, a disposable electrode is stored in a state where it is placed in a sealed container. However, such a gel deteriorates with time, and has a possibility of changing to an electrical state which is not adequate as an electrode. Therefore, an expiration date is defined, and printed on the sealed container or the like.
The user must check the printed expiration date, and prepare a disposable electrode which has not passed the expiration date. In a defibrillator, moreover, also a training electrode is used in order to conduct practice training to provide for an emergency. In the case where a training electrode is connected to a defibrillator, the operation sequence is not advanced until a regular electrode is connected, from the viewpoint of avoiding the risk.
In the present state of the art of defibrillators and their electrodes, unless the user pays adequate attention, it is impossible to eliminate the possibility that, in case of emergency, a situation occurs where the expiration date has been passed, or where a training electrode remains connected to a defibrillator.
By contrast, a defibrillator is known which includes a plurality of coupling points that, when an electrode connector is connected to a main-unit connector, can recognize the type of the electrode. Such a defibrillator is configured so as to detect also that an electrode is not connected thereto (JP-A-8-168536, particularly see paragraphs 0017 to 0020).
Moreover, also a defibrillation electrode is known in which a connector for the electrode includes an internal use paddle electrode and an adhesive type electrode includes an identifying signal producing circuit that is configured by a resistor, and that produces an identifying signal indicative of an internal electrode (see FIG. 9 and paragraph 0024 of JP-A-2001-218854).
Furthermore, also a biosensor is known in which information including an expiration date is stored in an IC tag or a memory element, and the information is read out by a reading apparatus (see JP-A-2006-275724 and JP-A-2006-275923).
Furthermore, it is contemplated that, in an electrode-side connector which connects an electrode to a defibrillator main unit, a semiconductor device such as a memory element for storing an expiration date and the type of the electrode is disposed.
In the connector disclosed in JP-A-8-168536, when the amount of information is to be increased, the coupling points must be increased, and there is a possibility that the size or the production cost is increased by the augmented configuration. The circuit disclosed in JP-A-2001-218854 is configured by a resistor, and hence the accuracy is problematic. Moreover, there is a possibility that erroneous recognition occurs due to a temporal change or a temperature change of the resistance.
The IC tag or memory element disclosed in JP-A-2006-275724 and JP-A-2006-275923 is relatively expensive, and hence is not appropriate for the use in a disposable electrode. There is a further problem in that the reading apparatus has a relatively large-scaled configuration.
In the configuration in which a resistor, a semiconductor device, or the like is disposed in a connector, an electrical component such as the resistor or the semiconductor device must be placed in a narrow place. In disposition of an electrical component, a phenomenon that an unexpected voltage is applied to a patient body by, for example, contacting the component with another terminal must be definitely avoided. Therefore, the configuration and cost for avoiding the phenomenon are inevitably increased.